How much active ingredient is there in a 20-pound bag of atrazine 90 DF?

• A. 18 pounds
• B. 20 pounds
• C. 9 pounds
• D. 2 pounds

Answer: (A)

This item tests understanding of labeled active ingredient content in a pesticide formulation. A label that shows atrazine 90 DF means the product is 90 percent active ingredient by weight, with the remainder being inert carriers. To find how much active ingredient is in a bag, multiply the total weight by the percent active: 20 pounds × 0.90 = 18 pounds of active ingredient. The rest (2 pounds) is inert material. So the active ingredient amount is 18 pounds.